1. Field
The present teachings relate to heat exchangers and, in particular, relates to a heat exchanger having powder coated elements that inhibit corrosion.
2. Description of the Related Art
Heat exchangers in various forms are included in systems that control the condition of air. Conventional heat exchangers include a heater that takes input air and outputs air with a higher temperature. A cooler, generally referred to as an air conditioner, takes input air and outputs air with a lower temperature. In both cases, the change in temperature is achieved by some form of a heat exchanger. In a heater, air is typically blown past a heated element such that heat is transferred from the heated element to the air. In a cooler, air is typically blown past a chilled element such that heat is transferred from the air to the chilled element.
A rotary heat exchanger is an apparatus that exchanges heat with relatively large volumes of air. The rotary heat exchanger typically comprises a cylindrically shaped device that permits air to flow therethrough. Typically, heat exchange is achieved by flowing both the input air and exhaust air through the rotating rotary heat exchanger at two different locations. Heat exchange elements in the exchanger remove heat from one flow of air and release the heat to the other flow of air. The rotational speed can be selected to permit efficient overall heat transfer.
In operation, the heat exchangers are usually exposed to harsh environments that tend to induce corrosion of the metal of the heat exchanger, including the seals and the heat exchange elements. The corrosive environment leads to pitting in the degeneration of the metal in the heat exchange elements, structurally weakening the elements. To counter the corrosion problems, traditional heat exchange elements often have an enamel coating applied to the surface of the metal. Often, the enamel coating contains bubbles such that full corrosion protection is not afforded. In addition, the enamel coating is susceptible to cracking when subjected to mechanical stresses. Such breach of the coating allows corrosion inducing agents to come in contact with the metal, thereby causing corrosion, which in turn reduces the effectiveness of the heat exchanger.
From the foregoing, it will be appreciated that there is a need for an improved method of fabricating a heat exchanger. To this end, there also exists a need for an improved method of protecting the metal of the heat exchange elements so as to provide improved corrosion resistance.